Internal combustion engine



Sept. 7, ,1937. A. R. WURTELE 2,092,384

INTERNAL COMBUSTION ENGINE Original Filed July 30, 1954 IN VEN TOR.

m fw

ATTORNEY Patented Sept. 7, 1937 UNITED STATES PATENT OFFIQE Original application July 30, 1934, Serial No. 737,505. Divided and this application September 11,1935, Serial No. 40,010

8 Claims. (01. 123-32) This invention relates to internal combustion engines and more particularly to engines wherein the fuel is ignited in a precombustion chamber.

This application constitutes a division of applicants prior application Serial No. 737,505, filed July 30, 1934. a

One of the objects of the present invention is to provide a novelcombination of valve, cylinder and piston construction whereby better cooling and more complete combustion are obtained.

Another object is to provide novel valve and piston constructions which cooperate with the engine power cylinder to form a novel and efficient combustion chamber.

A further object is to provide an internal combustion engine, having precombustion chambers, which is so constructed that greater turbulence of air in the main combustion chambers is obtained, resulting in increased efficiency in the burning of the fuel, the air currents being such as to aid the flow of air from the precombustion chamber and to prevent overheating of the piston crown.

Theabove and further objects and novel fea tures of this invention will more fully appear from the following detailed description, taken'in connection with the accompanying drawing, wherein one embodiment of the invention is shown in side elevation, partly in section and with parts broken away. It is to be expressly understood, however, that the drawing is for the purpose of illustration only and is not designed as a definition of the limits of the invention, reference being primarily had for this purpose to the appended claims.

In the drawing, wherein like reference characters refer to like parts throughout the several views,

Fig. 1 is a side elevation, partly in section and With parts broken away, of a portion of an internal combustion engine embodying one form of the present invention; and,

Fig. 2 is a detail view, partly in section and with parts broken away, the section being taken on line 2-2 of Fig. 1. 1

The invention is illustrated, by way of example, in a two-cycle, exhaust-valve-in-head, port-scavenging, solid-fuel injection engine. In the form 50 shown, a cylinder 5, a water jacket 6 therefor,

anda cylinder head 1 are preferably cast integra'lly with each other. Head 1 is provided with a cooling chamber 9 which is in communication with a chamber 50 between the outer wall of cylinder 5 and jacket 0. A suitable cooling medium may be circulated through said chamber in the usual manner.

A piston H is adapted to reciprocate in cylinder 5, the same being connected by means of a connecting rod l2 to the engine crankshaft (not shown). Surrounding said cylinder at a point slightly above piston II when the latter is at the bottom of its stroke is' an air box l3 which is in constant communication through conduit M with a source of compressed air. Cylinder 5 is connected to said air box by a plurality of ports It: in the wall of said cylinder, said ports preferably being cut at an angle such as to admit air in a tangential direction, thereby generating a swirling column of air in the cylinder when piston II is near the bottom of its stroke.

An exhaust gas port It surrounded by a valve seat is provided in cylinder head I, said port being concentric with cylinder 5 and opening into an A exhaust gas passage IT. A valve having an enlarged head portion l8 and a hollow stem [9 adapted to operate in a valve guide 20 controls the passage of exhaust gases through port it. Any suitable means (not shown) may be provided for normally holding valve l8, l9 in closed position and for opening the same just prior to the uncovering of inlet ports I5 by piston H on the downward movement of the latter. Measured quantities of fuel are pumped through a hollow U spindle 2i centrally disposed in stem I9, past a valve 22 and into a precombustion chamber 23 formed in valve head l8, said fuel preferably being sprayed into said chamber through an atomizing nozzle 24. The annular space between spindle 2| and stem l9 may be employed as a cooling chamber through which the engine fuel or other suitable cooling medium may be circulated. Piston II and valve l8, l9 are constructed in a novel manner and cooperate to form a novel combustion chamber in cylinder 5 when said piston is at the top of its stroke and to set up air currents which are effective, in a manner to hereinafter appear, to increase efiiciency and improve the operating characteristics of the engine. As shown, the face 25 of valve I8, I9 is arcuate and extends downwardly into cylinder 5. A cup or recess 25, having a contour substantially the same as valve face 25, is provided in the crown of piston ll, said valve being adapted to extend into said cup when the piston isat the topof its stroke, 1. e. in the position illustrated. An annular combustion chamber 2'! is thus formed which communicates with precombustion chamber 23 through a plurality of orifices 28 in valve face 25.

As heretofore pointed out, valve l8, I9 is opened when piston II nears the bottom of its stroke uncovering inlet ports [5. The inrushing air drives the burned gases out through port IS, the gases in the center of the cylinder flowing freely around valve head l8 because of the streamline curvature of valve face 25, thus thoroughly scavenging cylinder 5. On the upstroke of piston ll, valve l8, I9 is preferably closed just prior to the closure of ports I by the piston, thereby permitting some supercharging of cylinder 5 through said ports. Further upward movement of piston ll closes ports I5 and compresses the air or other combustion supporting medium in cylinder 5.

As the piston nears the top of its stroke, a charge of fuel is pumped into precombustion chamber 23 where it is started burning by the heat of compression of air entering said chamber through orifices 28 from cylinder 5. The burning fuel expands and is being driven out into cylinder 5 as the lower point of valve face 25 is entering recess 26. The entrance of said valve face into said recess is effective to drive the air from the central portion of cylinder 5, setting up air currents flowing upwardly into annular combustion chamber 21, and substantially tangential to the outer ends of ports 28. These currents are deflected by the walls of said chamber and combine with the annular currents set up by the entrance of air through tangential ports l5, thereby creating a turbulence in chamber 21 which is particularly conducive to complete and rapid combustion of the fuel. The speed of combustion is also enhanced by the increased compression obtained as a result of the decreased clearance volume when piston II is at the top of its stroke, as shown in the drawing.

Additionally, the radial currents are effective to blow the burning fuel away from the piston crown, thus preventing overheating and burning of the same. Furthermore, these currents rushing across the top of piston H and valve face 25 tend to cool the same. Since the fuel is burned primarily in annular combustion chamber 21, the heat of combustion is absorbed chiefly by the cylinder wall and carried away by the cooling medium circulating in cooling chamber 9, ID. The air rushing from the space between valve face 25 and recess 26 also produces an ejector effect as it passes orifices or ports 28, thereby drawing the partially burned fuel from precombustion chamber 23 into chamber 21 where the energy of the same will be expended to drive piston ll downwardly again.

There is thus provided a novel combination of elements in an internal combustion engine wherein said elements cooperate to form a novel combustion space for a solid fuel and to set up air currents therein creating a turbulence of the combustion supporting medium and fuel which materially aids combustion, thus insuring complete combustion and increased operating efficiency. The construction provided. is also such that the turbulence which thus aids combustion is brought about at the most opportune instant in relation to the position of the power piston, i. e. near top dead center. The speed of combustion is also increased thus enhancing the power output per unit of energy input. Although only one embodiment of the invention is illustrated and described, it is to be expressly understood that the same is not limited thereby but that various changes may be made in the design and arrangement of parts illustrated, as will now be apparent to those skilled in the art, without departing from the spirit of the invention. Reference will be had primarily to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. In an internal combustion engine, a power cylinder, a piston operable in said cylinder, said piston having a centrally disposed recess in the upper face thereof, a cylinder head for said cylinder having a centrally disposed port therein, and a valve having an enlarged head portion and a hollow stem for controlling the passage of exhaust gases through said port, said valve having a precombustion chamber in the head thereof and having the face thereof shaped to conform to the recess in said piston, thereby forming an annular combustion chamber in said cylinder, said last named chamber being in communication with said precombustion chamber through orifices in said valve face.

2. In an internal combustion engine, a power cylinder, a cylinder head therefor having a centrally disposed port therein, a valve for said port having a convex face and having a precombustion chamber in the head thereof, and a piston 3 operable in said cylinder having a cavity in the top thereof conforming to the surface of the lower portion of said valve face to form an an-- nular combustion space in said cylinder when the piston is at the top of its stroke.

3. In an internal combustion engine, a power cylinder having inlet ports in the vertical walls thereof, a piston operable in said cylinder adapted to cover and uncover said ports, a cylinder head for said cylinder having a centrally disposed exhaust port therein, a valve for said exhaust port, a portion of the face of said valve being adapted to extend into a recess in the top of said piston when the latter is at the top of its. stroke to form an annular combustion chamber, and means for introducing fuel into said chamber through the stem of said valve.

4. In combination, a cylinder, a piston therein having a recess in the head thereof, and an exhaust valve for the cylinder, said valve having a precombustion chamber in the head thereof, the head having openings therethrough and the lower surface thereof conforming to the recess in the piston, movement of the piston toward the valve being adapted to cause the valve head to enter the piston recess whereby gases are forcedfrom the recess past the outer ends of said openings.

5. In combination, a cylinder, an exhaust valve positioned centrally of the head of said cylinder, a piston having a recess in the upper end there'- of, the valve having a ported precombustion chamber in the head thereof and the lower surface of the head conforming to the recess in the piston whereby an annular combustion space is formed in the cylinder by the valve and piston when the latter is at the top of its stroke, the movement of the piston being adapted to force gases from the recess past the ports in the valve head.

6. In an internal combustion engine, a power cylinder, a cylinder head therefor, a precombustion chamber having a convex wall portion extending downwardly from said cylinder head into said cylinder, and a piston operable in said cylinder having a cavity in the top thereof conforming to the surface of said convex wall portion of the precombustion chamber to form an annular combustion space in said cylinder when the piston is at the top of its stroke.

7. In an internal combustion engine, a power cylinder, a cylinder head therefor, a precombustion chamber having a convex wall portion extending downwardly from said cylinder head into said cylinder, said convex wall portion having a plurality of openings connecting said chamber and cylinder, and a piston operable in said cylinder having a cavity in the top thereof conforming to the surface of said convex wall portion below said openings'to form an annular combustion space in said cylinder when the piston is at the top of its stroke.

8. In an internal combustion engine, a power cylinder, a piston operable therein, a cylinder head for said cylinder having a port, a valve for said port, a portion of the face of said valve being adapted to extend into a recess in the top of said piston when the latter is at the top of its stroke to form an annular combustion chamber, and means for introducing fuel into said chamber.

ALLAN R. WURTELE. 

